class_docstr: Residual block.
code: def __call__(self, x):
      main_branch = hk.Sequential(
          [
              jax.nn.relu,
              hk.Conv2D(
                  self._num_channels,
                  kernel_shape=[3, 3],
                  stride=[1, 1],
                  padding="SAME",
              ),
              jax.nn.relu,
              hk.Conv2D(
                  self._num_channels,
                  kernel_shape=[3, 3],
                  stride=[1, 1],
                  padding="SAME",
              ),
          ]
      )
      return main_branch(x) + x
  
imports: import collections
  import dm_env
  import haiku
  import jax.nn
  import jax.numpy
label_desc: Use image node_id 2 for calling the ResidualBlock obj's underlying member method code with example usage: obj.__call__(x) and returns: unknown